{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T07:00:37Z","timestamp":1785308437651,"version":"3.55.0"},"reference-count":20,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>The COVID-19 pandemic was associated with substantial changes in cancer diagnosis and treatment. This study aimed to assess changes in colorectal cancer diagnostics during the COVID-19 pandemic by analyzing changes in tumor stage and the number of newly diagnosed cases across different pandemic waves and the post-COVID period using MRI-based data.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>The study included 198 patients with colorectal cancer, 43 with a new diagnosis. The study period was divided into five COVID-19\u2013related intervals. The number of newly diagnosed cases across COVID-19 waves was compared using one-way ANOVA. Stage distribution differences were assessed using Fisher\u2019s exact test. In follow-up patients, changes were analyzed using the Wilcoxon signed-rank test. Secondary outcomes included tumor changes, number of missed treatments, and the presence of metastases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Monthly averages of newly diagnosed colorectal cancer cases were lower during the COVID-19 waves than in the post-COVID period (p &amp;lt; 0.001). Although overall tumor stage did not differ between waves, larger tumors were more frequent during the COVID-19 waves, whereas early-stage (T1) tumors were more common in the late\/post-COVID period (p &amp;lt; 0.001). Tumor stage distribution also differed between the COVID and post-COVID periods, with a shift toward earlier-stage disease after the pandemic (p = 0.002). No differences were observed in missed treatments across COVID-19 periods (p-value &amp;gt; 0.05).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>The COVID-19 pandemic was associated with a lower number of newly diagnosed colorectal cancer cases during the pandemic and a higher proportion of patients presenting with more advanced disease stages. These findings suggest an association with pandemic-related healthcare disruption; however, causality cannot be established.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link>https:\/\/clinicaltrials.gov\/<\/jats:ext-link>\n                      , identifier NCT07328399.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fonc.2026.1837204","type":"journal-article","created":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T06:03:29Z","timestamp":1785305009000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of COVID-19 pandemic waves on colorectal cancer stage migration and diagnostic delays"],"prefix":"10.3389","volume":"16","author":[{"given":"Klaudia","family":"Sz\u00e9phelyi","sequence":"first","affiliation":[{"name":"Doctoral School of Health Sciences, Faculty of Health Sciences, University of P\u00e9cs","place":["P\u00e9cs, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adrienn","family":"Bir\u00f3","sequence":"additional","affiliation":[{"name":"Doctoral School of Health Sciences, Faculty of Health Sciences, University of P\u00e9cs","place":["P\u00e9cs, Hungary"]},{"name":"Somogy County Kaposi M\u00f3r Teaching Hospital","place":["Kaposv\u00e1r, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00f3zsef","family":"Toll\u00e1r","sequence":"additional","affiliation":[{"name":"Doctoral School of Health Sciences, Faculty of Health Sciences, University of P\u00e9cs","place":["P\u00e9cs, Hungary"]},{"name":"Somogy County Kaposi M\u00f3r Teaching Hospital","place":["Kaposv\u00e1r, Hungary"]},{"name":"Digital Development Center, Sz\u00e9chenyi Istv\u00e1n University","place":["Gy\u0151r, Hungary"]},{"name":"Faculty of Health Sciences, University of P\u00e9cs","place":["P\u00e9cs, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.3390\/cancers13030408","article-title":"Impact of the COVID-19 pandemic on cancer diagnoses in general and specialized practices in Germany","volume":"13","author":"Jacob","year":"2021","journal-title":"Cancers"},{"key":"B2","unstructured":""},{"key":"B3","article-title":"A COVID-19 vil\u00e1gj\u00e1rv\u00e1ny hat\u00e1sa a daganatos betegek ell\u00e1t\u00e1s\u00e1ra","volume":"99","author":"Mayer","year":"2022","journal-title":"N\u00e9peg\u00e9szs\u00e9g\u00fcgy"},{"key":"B4","article-title":"A COVID-19 hat\u00e1sa az eg\u00e9szs\u00e9g\u00fcgyre","volume-title":"Inform\u00e1ci\u00f3s Jegyzet 2023 2023\/5","year":"2023"},{"key":"B5","unstructured":"R\u00e1k\u00fcgyi Orsz\u00e1gprofil \u2013 Magyarorsz\u00e1g 2025 [Cancer Country Profile \u2013 Hungary 2025]\n          \n          2025"},{"key":"B6","unstructured":""},{"key":"B7","unstructured":""},{"key":"B8","unstructured":""},{"key":"B9","volume-title":"Dashboard","author":"Covid","year":"2020"},{"key":"B10","volume-title":"AJCC Cancer Staging Manual. 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